1. Field of the Invention
The present invention relates generally to a clamping device for use with liquid and gaseous medium.
2. Problem to be Solved
(i) Background and Long-Felt Need
Recent international legislation engendered by environmental concerns over the issues of global warming and ozone depletion have mandated the elimination of Chloro-Fluorocarbons or CFCs including those used in the multi-billion dollar air conditioning/refrigeration industry. Substitute refrigerants that have more beneficial environmental indices, such as R134a (a replacement for R12 which is widely used in the automotive industry), are now used in conventional air conditioning/refrigeration systems. Consequently, new SAE (Society of Automotive Engineers) standards, such as J2064, have been promulgated which have raised integrity standards for R-134a automotive air conditioning hose couplings above those of the R-12 hose couplings.
It has been found that leakage can occur when conventional rubber hoses and barb couplings or fittings, designed for use with R-12 refrigerants, are used with R-134a refrigerant. There are two causes for this leakage: (1) increased permeation rate through the hose due to the smaller molecular size of the R-134a refrigerant, and (2) plastic deformation of the hose material at the hose coupling. These causes of leakage were verified by laboratory tests conducted on configurations comprising conventional R-12 refrigerant hoses and screw clamps. The aforementioned leakage occurred between the R-12 refrigerant hose and the barb coupling and was caused by loss of compression of the hose material due to plastic deformation and hose permeation. The plastic deformation effected a reduction in torque of the screw clamp. The reduction in torque of the screw clamp effected a reduction in the clamping force applied to the hose material. Increasing the torque of the screw clamp significantly increased the leakage because the resulting increases in material compression caused plastic deformation to occur at these higher torque levels.
(ii) Objects of the Present Invention
Bearing in mind the problems and deficiencies in conventional clamping devices, it is an object of the present invention to provide a new and improved clamping system that meets the new SAE requirements for R-134a refrigerant.
It is another object of the present invention to provide a new and improved clamping system that comprises a double seal arrangement wherein a first seal reduces the pressures experienced by a second seal.
It is another object of the present invention to provide a new and improved clamping system that utilizes a first clamping portion for placement over a high pressure portion of a hose-coupling joint, and a second clamping portion for placement over a low pressure portion of the hose-coupling joint.
It is a further object of the present invention to provide a new and improved clamping system that can be manufactured at reasonable costs.
It is yet another object of the present invention to provide a new and improved clamping system that does not require replacement of costly components such as heat exchangers.
It is yet a further object of the present invention to provide a new and improved clamping system that does not require replacement of costly components such as heat exchangers, in order to convert the heat exchanger system to use alternative ozone friendly refrigerants.
Other objects and advantages of the clamping system of the present invention will be apparent to one skilled in the art in light of the ensuing description.